The Joslin Genomics Core provides microarray analysis and expression profiling related to both rodent and human projects. The major format is based on Affymetrix oligonucleotide arrays. Expertise for preparation of cRNA probes and GeneChip analysis is already established in this Core; a partnership with Beth Israel Deaconess and Children's Hospital (through the NIDDK-sponsored Biotechnology Center grant) has been established for purposes of educational resources, training, and bioinformatics support. A more study-focused collaboration with the University of Massachusetts Core Facility is in the early stages, with the goal to compare and standardize the results in this laboratory with those in the U Mass facility. We ultimately plan that the Core will develop customized microarrays focusing on the insulin signaling/ diabetes candidate genes identified as a result of expression screening using the Affymetrix system. These will include genes highly regulated by insulin or diabetes in muscle, fat, liver, vascular tissue, and lymphocytes, as well provide screens for genetic polymorphisms identified using HuSNP arrays. These custom arrays will be made available to Joslin investigators and other qualified investigators in the U.S. and abroad.